An OLED (organic electroluminescent diode) display device has characteristics, such as a self-illumination, a wide view angle, a high luminous efficiency, a low power consumption, a fast responding time, a good low temperature characteristic, a simple manufacturing process, a low cost and so on, which has been widely used in the display field.
A core component of the OLED display device is an OLED display panel, and a structure of the OLED display panel usually includes: a TFT array substrate and an anode layer, a pixel defining layer, a first common layer, a light emitting layer, a second common layer and a cathode layer sequentially manufactured on the TFT substrate. The anode layer includes a plurality of anodes arranged in an array, and the pixel defining layer includes a plurality of pixel openings corresponding to the anodes one by one; the first common layer completely covers the pixel defining layer and the anode layer (continually covering through an entire surface in the structure layer), and the first common layer may include a plurality of sub function layers; the light emitting layer includes a plurality of light emitting units corresponding to the pixel openings one by one, and the light emitting units are located in the pixel openings; the second common layer completely covers the light emitting layer and the first common layer (continually covering through an entire surface in the structure layer), and the first common layer may include a plurality of sub function layers; and the cathode layer is covered on the second common layer.
A working principle of the OLED display panel is that, under the effect of an electric field between the anode and the cathode, holes are transferred to the light emitting layer through the first common layer, electrons are transferred to the light emitting layer through the second common layer, and the holes and the electrons are combined in the light emitting layer thereby emitting light. The OLED display panel usually realizes a display effect of different colors by a mixture of R, G, B three primary colors, thus one pixel of the OLED display panel usually includes R, G, B three light emitting units, and R, G, B three light emitting units of each pixel can be separately controlled by a driving circuit. To be specific, the cathode layer of the R, G, B three light emitting units is common, and the anode layers are independent to each other, and a separate driving of each light emitting unit may be realized by controlling the anode corresponding each light emitting unit.
As the resolution of the display panel increases, the number of light emitting units per unit area also increases continuously, as a result, intervals between the light emitting units decreases continuously, in addition, in order to improve display efficiency, many excellent transport materials have been introduced to the first common layer for transferring holes. In the case where the intervals between the light emitting units decreases and the transfer performance of the first common layer increases continuously, a transverse current of the display panel also increases, which causes a crosstalk. To be specific, in the structure of the existing OLED display panel as mentioned above, since the first common layers of the adjacent light emitting units are connected, when one of the light emitting units (a target light emitting unit) is lit, a small amount of holes can be injected into the adjacent light emitting unit through the first common layer, and combined with the electrons in the adjacent light emitting unit thereby emitting light, which causes that light emitted by the target light-emitting unit is impure, this light-emitting phenomenon is called as the leaked light-emitting phenomenon, and a current formed by a small amount of leaked holes is called as a leakage current. Especially when the target light emitting unit is lit under a low current, since the light emitted by the target light emitting unit is also weak, the performance of the light leakage phenomenon is obvious at this time, and thereby the display quality of the OLED display panel is reduced.